[ 
https://issues.apache.org/jira/browse/HDFS-17120?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17747300#comment-17747300
 ] 

ASF GitHub Bot commented on HDFS-17120:
---------------------------------------

sadanand48 commented on PR #5885:
URL: https://github.com/apache/hadoop/pull/5885#issuecomment-1651055042

   Thanks @umamaheswararao @swamirishi for the review, I have now updated the 
patch to use a flag instead of a new copyListing type. Please take a look.




> Support snapshot diff based copylisting for flat paths.
> -------------------------------------------------------
>
>                 Key: HDFS-17120
>                 URL: https://issues.apache.org/jira/browse/HDFS-17120
>             Project: Hadoop HDFS
>          Issue Type: Bug
>            Reporter: Sadanand Shenoy
>            Assignee: Sadanand Shenoy
>            Priority: Major
>              Labels: pull-request-available
>
> Currently for Diff-based copyListing that is used during the distcpSync step 
> of an incremental copy by default the SimpleCopyListing implementation is 
> used.  In it's implementation it iterates through the DiffReport and if the 
> DiffType is Create and the path is a directory, it recursively traverses the 
> directory and adds the subpaths to the resultant copyList.
> This works fine for implementations of snapshotDiff that include only 
> top-level directories as part of its DiffReport . Suppose a snapshotDiff 
> implementation outputs only flat paths that include both the directory and 
> sub-directory subpath in its DiffReport, it will lead to duplicate paths in 
> the copyList and throws DuplicateFileException.
>  
> For example
> Ozone filesystem implementation of snapdiff b/w 2 snapshots shows all 
> subpaths as part of the diff.
> {code:java}
> [~]# ozone sh snapshot create vol11/buck1 snap1
> [~]# ozone sh snapshot create vol11/buck2 snap1
> [~]# ozone fs -mkdir ofs://ozone1/vol11/buck1/dir1
> [ ~]# ozone fs -mkdir ofs://ozone1/vol11/buck1/dir1/dir11
> [ ~]# ozone fs -mkdir ofs://ozone1/vol11/buck1/dir1/dir11/dir111
> [~]# ozone sh snapshot create vol11/buck1 snap2 
> [~]# ozone sh snapshot diff vol11/buck1 snap1 snap2
> Difference between snapshot: snap1 and snapshot: snap2
> +    ./dir1
> +    ./dir1/dir11
> +    ./dir1/dir11/dir111  {code}
> we can see even though dir11 & dir111 are subpaths they are present in 
> snapdiff , This is not the case for HDFS though.
> This Jira aims to create a new copyListing impl that is used for diff based 
> copyListing that doesn't traverse the directory but only adds paths that are 
> present in its diff.



--
This message was sent by Atlassian Jira
(v8.20.10#820010)

---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org

Reply via email to